Temperature control system for semiconductor manufacturing equipment

ABSTRACT

A temperature control system for semiconductor manufacturing equipment is disclosed, which can properly cool a process chamber adopted in the semiconductor manufacturing equipment such as a wafer etching device. The temperature control system for semiconductor manufacturing equipment includes a thermocline for cooling heat transfer fluid accommodated therein through a heat exchange with a heat exchanger and storing heat energy, a supply line for controlling the temperature of the heat transfer fluid in the thermocline through a heater and supplying the heat transfer fluid with a proper temperature to a process device, a recovery line for forwarding the heat transfer fluid having passed through the process device to the thermocline, and a bypass for forwarding a part of the heat transfer fluid passing through the recovery line to the supply line through the heater.

TECHNICAL FIELD

The present invention relates to semiconductor manufacturing equipment,and more particularly to a temperature control system for semiconductormanufacturing equipment, which can properly cool a process chamberadopted in the semiconductor manufacturing equipment such as a waferetching device.

BACKGROUND ART

Generally, semiconductor devices and semiconductor chips aremanufactured by processing a wafer formed of silicone usingsemiconductor equipment. That is, in order to manufacture thesemiconductor device or semiconductor chip, a wafer is typicallyprocessed through a series of semiconductor processes such aslithography, chemical or physical deposition, plasma etching, and soforth.

The quality of the semiconductor device or semiconductor chip may differdepending on variables such as the quality of a wafer, a waferprocessing method, and so forth. One of important variables inmanufacturing the semiconductor device is the temperature of a wafersurface. If the surface temperature of the wafer is not uniform, theetching rate of the wafer surface may differ. Accordingly, by uniformlycontrolling the temperature of the wafer surface, a semiconductor devicehaving a higher quality can be manufactured.

Typically, the adjustment of the surface temperature of the wafer isperformed by adjusting the temperature of a wafer chuck on which thewafer is mounted. Generally, the temperature of the wafer chuck has beenadjusted by flowing fluid of a constant temperature provided through achiller or a heat exchanger into the wafer chuck.

FIG. 1 illustrates the construction of a conventional temperaturecontrol system for semiconductor manufacturing equipment.

According to the conventional temperature control system forsemiconductor manufacturing equipment as illustrated in FIG. 1, coolingwater or coolant that flows through lines L1 and L2 transferslow-temperature heat energy to coolant existing in a reservoir 2 througha heat exchanger 1 to cool the coolant, and then the cooled coolant inthe reservoir 2, which is pumped by a pump 3, is supplied to a processdevice 4, i.e., a wafer chuck, connected to the reservoir 2 through thelines L3 and L4 to lower the temperature of the wafer chuck.

However, the conventional temperature control system for semiconductormanufacturing equipment having the above-described construction requiresa large amount of electricity in controlling the process temperature,and this causes a large amount of energy to be consumed with the heatefficiency lowered.

Further, since the conventional temperature control system controls alarge amount of fluid, it takes a lot of time for reaching a desiredtemperature of the wafer chuck, and the speed to cope with the load islowered.

Furthermore, in the case of the general semiconductor manufacturingequipment, the temperature control system as illustrated in FIG. 1should be provided for each process device to control the temperature ofthe process device, and this causes the increase of installation costand scale of the temperature control system.

DISCLOSURE Technical Problem

The present invention has been made in view of the foregoing problems,and it is an object of the present invention to improve the structure ofa temperature control system for semiconductor manufacturing equipmentso as to improve the energy efficiency of the semiconductormanufacturing equipment.

It is another object of the present invention to improve the structureof a temperature control system for semiconductor manufacturingequipment so that the temperature of a heat transfer fluid beingsupplied to a process chamber of a process device can be promptlycontrolled at a desired temperature level.

It is still another object of the present invention to improve thestructure of a temperature control system for semiconductormanufacturing equipment so that the temperatures of several processdevices can be controlled using one temperature control system.

Technical Solution

In order to achieve the above objects, in one aspect of the presentinvention, there is provided a temperature control system forsemiconductor manufacturing equipment, which includes a thermocline forcooling heat transfer fluid accommodated therein through a heat exchangewith a heat exchanger and storing heat energy; a supply line forcontrolling the temperature of the heat transfer fluid in thethermocline through a heater and supplying the heat transfer fluid witha proper temperature to a process device; a recovery line for forwardingthe heat transfer fluid having passed through the process device to thethermocline; and a bypass for forwarding a part of the heat transferfluid passing through the recovery line to the supply line through theheater.

In another aspect of the present invention, there is provided atemperature control system for semiconductor manufacturing equipment,which includes a circulation line for supplying heat transfer fluid to aprocess device and then recovering the supplied heat transfer fluid; athermocline for cooling the heat transfer fluid accommodated thereinthrough a heat exchange with a heat exchanger, storing heat energy,receiving a part of the heat transfer fluid circulating through thecirculation line, and then supplying the part of the heat transfer fluidaccommodated therein to the circulation line; and a heater forcontrolling a temperature of the heat transfer fluid being supplied tothe process device through the circulation line at a proper temperaturelevel.

The temperature control system according to embodiments of the presentinvention may further include a proportional control valve forcontrolling a flow of the heat transfer fluid so that a flow rate of theheat transfer fluid flowing into the thermocline through the processdevice and a flow rate of the heat transfer fluid being discharged to besupplied from the thermocline to the process device substantiallycoincide with each other.

The thermocline may include a phase change material (PCM) pipe forstoring thermal energy using a PCM.

The temperature control system according to embodiments of the presentinvention may further include a plurality of process devices connectedto the thermocline so that the thermocline supplies the heat transferfluid to the respective process devices.

The temperature control system according to embodiments of the presentinvention may further include an auxiliary bypass for supplying to theheater the part of the heat transfer fluid being supplied to the processdevice through the heater.

Advantageous Effects

According to the temperature control system for semiconductormanufacturing equipment according to the present invention asconstructed above, the heat transfer fluid to be supplied to the processdevice is cooled by the thermocline using the thermal storage and latentheat, a small amount of heat transfer fluid flowing through the supplyline is heated to a desired process temperature by the heater, and theheat of the heat transfer fluid being recovered to the thermoclinethrough the process device is used to control the temperature of theheat transfer fluid being supplied to the process device. Accordingly,the temperature control system for semiconductor manufacturing equipmentaccording to the present invention has a higher heat efficiency thanthat of the general temperature control system.

In addition, since the temperature control system according to thepresent invention controls the temperature of only a small amount ofheat transfer fluid, it can promptly cope with a required load.

In addition, according to the temperature control system according tothe present invention, several process devices can be connected to onethermocline. Accordingly, the temperatures of the several processdevices can be controlled using the heat transfer fluid stored in thethermocline, and thus the installation cost and scale can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of the presentinvention will become more apparent from the following detaileddescription when taken in conjunction with the accompanying drawings inwhich:

FIG. 1 is a block diagram schematically illustrating the construction ofa conventional temperature control system for semiconductormanufacturing equipment;

FIG. 2 is a block diagram schematically illustrating the construction ofa temperature control system for semiconductor manufacturing equipmentaccording to a first embodiment of the present invention;

FIG. 3 is a block diagram schematically illustrating the construction ofa temperature control system for semiconductor manufacturing equipmentaccording to a second embodiment of the present invention;

FIG. 4 is a block diagram schematically illustrating the construction ofa temperature control system for semiconductor manufacturing equipmentaccording to a third embodiment of the present invention; and

FIG. 5 is a block diagram schematically illustrating the construction ofa temperature control system for semiconductor manufacturing equipmentaccording to a fourth embodiment of the present invention.

BEST MODE

Reference will now be made in detail to a chiller system forsemiconductor manufacturing equipment according to the preferredembodiments of the present invention with reference to the accompanyingdrawings.

FIG. 2 illustrates the construction of a temperature control system forsemiconductor manufacturing equipment according to a first embodiment ofthe present invention. Hereinafter, the temperature control system forsemiconductor manufacturing equipment according to the first embodimentof the present invention will be described with reference to FIG. 2.

As illustrated in FIG. 2, a thermocline 100 cools heat transfer fluidaccommodated therein by exchanging heat with a heat exchanger 10. Inaddition, the thermocline 100 stores therein the heat-exchanged energy.For this, in the thermocline 100, a phase change material (PCM) pipe 110is provided to store the heat-exchanged energy in a PCM. Since thethermal storage technique using the PCM is well known, furtherdescription thereof will be omitted.

In the temperature control system for semiconductor manufacturingequipment according to the first embodiment of the present invention,the heat exchanger 10 that exchanges heat with the thermocline 100, asillustrated in FIG. 2, may be provided with an evaporator 10 having acooling cycle. The heat exchanger 10, i.e., the evaporator, is connectedin order to a compressor 20, a condenser 30, and an expander 40. Coolantin the heat exchanger 10 passes in order through the compressor 20, thecondenser 30, and the expander 40, and then is returned to the heatexchanger 10, i.e., the evaporator.

The compressor 20 compresses a low-pressure gaseous coolant into ahigh-temperature high-pressure gaseous coolant, and the condenser 30condenses the compressed high-temperature high-pressure gaseous coolantinto a low-temperature liquid coolant by making the high-temperaturehigh-pressure gaseous coolant exchange heat with an outside. In order tocool the coolant in the condenser 30, cooling water is supplied to thecondenser 30. The liquid coolant having condensed through the condenser30 is expanded through the expander 40, and then is gasified through theheat exchanger 10, i.e., the evaporator. Since the coolant absorbs heatfrom the heat exchanger 10 when it is gasified in the heat exchanger 10,the heat exchanger 10 is abruptly cooled. Accordingly, the thermocline100 cools the heat transfer fluid accommodated therein by exchangingheat with the cooled heat exchanger 10, and then stores therein theheat-exchanged energy using the PCM pipe 110.

Then, the heat transfer fluid accommodated in the thermocline 100 issupplied to a process device 510, i.e., a wafer chuck, of thesemiconductor manufacturing equipment to properly maintain thetemperature of a wafer. This process will be described in more detailwith reference to FIG. 2.

The thermocline 100 and the process device 510 are connected through asupply line 200 and a recovery line 300. The supply line 200 suppliesthe heat transfer fluid in the thermocline 100 to the process device510, and the recovery line 300 recovers and forwards the heat transferfluid, which has been used to control the temperature of the wafer inthe process device 510, to the thermocline 100. In the supply line 200,as illustrated in FIG. 2, a pump 220 for pumping and forwarding the heattransfer fluid to the process device 510 may be installed.

In the supply line 200, a pressure gauge 230 for measuring the pressureof the heat transfer fluid being supplied to the process device 510through the supply line 200 may be installed, and in the recovery line300, a flow meter 320 for measuring the flow rate of the heat transferfluid flowing in the recovery line 300 may be installed. The amount ofheat transfer fluid, which is supplied to the process device 510 througha valve provided in the supply line 200, can be controlled based on datameasured by the pressure gauge 230 and the flow meter 320.

As illustrated in FIG. 2, a heater 210 is installed on the supply line200. The heater 210 serves to keep the temperature of the heat transferfluid to be supplied to the process device 510 at a proper temperaturelevel and to adjust the process temperature by exchanging heat with theheat transfer fluid being supplied to the process device 510. Here, theprocess temperature of the heat transfer fluid being supplied to theprocess device is kept in the range of about −30° C. to 180° C.,depending on the kind and characteristic of the process.

In order to maintain the heat transfer fluid being supplied to theprocess device 510 at a proper temperature, i.e., the processtemperature, the heater 210 does not heat the whole heat transfer fluidstored in the thermocline 100, but heats only a relatively small amountof heat transfer fluid flowing through the supply line 200. Accordingly,the energy efficiency is improved.

On the other hand, the whole amount of heat transfer fluid flowing tothe recovery line 300 through the process device 510 is not recovered tothe thermocline 100, but a part of the heat transfer fluid bypasses thethermocline 100 and is forwarded to the heater 210 installed on thesupply line 200. For this, a bypass 410 is connected to the supply line200 and the recovery line 300. Accordingly, the bypass 410, the supplyline 200, and the recovery line 300 form one circulation line, and theheat transfer fluid is circulated along the formed circulation line tobe supplied to and recovered from the process device 510.

The remainder of the heat transfer fluid not flowing into the bypass 410is recovered to the thermocline 100 through the recovery line 300. Also,a cold heat transfer fluid, the amount of which corresponds to theamount of the heat transfer fluid recovered to the thermocline 100, issupplemented to the supply line 200. The heat transfer fluid flowinginto the supply line 200 through the bypass 410 and the heat transferfluid supplemented to the supply line 200 are heated up to the processtemperature by the heater 210, and then is supplied to the processdevice 510.

On the recovery line 300 between the bypass 410 and the thermocline 100,as illustrated in FIG. 2, a proportional control valve 310 may beinstalled. The proportional control valve 310 serves as an actualcontrol valve. When a specified amount of heat transfer fluid normallycirculating is forwarded to the thermocline 100, the low-temperatureheat transfer fluid as much as the amount of heat transfer fluid beingforwarded flows into the thermocline 100 to lower the temperature of theheat transfer fluid circulating in the thermocline 100 to a desiredtemperature. In this case, the proportional control valve 310 serves tocontrol the temperature of the wafer in the process device 510 using theheat transfer fluid by adjusting the recovery rate and new supply rateof the circulating heat transfer fluid.

The proportional control valve 310 controls the flow of the heattransfer fluid so that the flow rate of the heat transfer fluid flowinginto the thermocline 100 through the process device 510 and the flowrate of the heat transfer fluid being discharged to be supplied from thethermocline 100 to the process device 510 substantially coincide witheach other. Accordingly, the thermocline 100 supplies to the circulationline the heat transfer fluid as much as the amount of heat transferfluid being recovered through the recovery line 300, under the controlof the proportional control valve 310.

As illustrated in FIG. 2, an auxiliary bypass 420 may be connected tothe supply line 200 and the bypass 410. The auxiliary bypass 420forwards to the bypass 410 a part of the heat transfer fluid beingheated to the process temperature by the heater 210 and then supplied tothe process device 510. The auxiliary bypass 420 facilitates the controlof the pressure and flow rate of the heat transfer fluid being pumped bythe pump 220 and forwarded to the process device 510 to facilitate therepair and maintenance of the process device 510.

Hereinafter the operation of the temperature control system forsemiconductor manufacturing equipment according to the first embodimentof the present invention will be described.

If the compressor 20 is operated, the heat exchanger 10 exchanges heatwith the thermocline 100. At an initial operation stage of thetemperature control system, since the compressor 20 is operated at ahigh speed, the heat transfer fluid in the thermocline 100 is rapidlycooled, and the PCM pipe 110 stores the cooled heat transfer fluid.After a specified time elapses, the heat energy accumulated in the PCMpipe 110 cools the heat transfer fluid in the thermocline 100 eventhough the output of the compressor 20 is lowered. Accordingly, thetemperature control system according to the present invention has ahigher heat efficiency than that of the conventional temperature controlsystem.

The heat transfer fluid in the thermocline 100 is heated to the processtemperature by the heater 210, and then is supplied to the processdevice 510. The heat transfer fluid supplied to the process device 510is used to control the temperature of the wafer, and the heat transferfluid having a heightened temperature flows into the recovery line 300.A part of the heat transfer fluid flowing into the recovery line 300 isforwarded to the heater 210 through the bypass 410, while the remainderthereof is recovered to the thermocline 100. The thermocline 100forwards to the heater 210 the cold heat transfer fluid as much as theamount of the recovered heat transfer fluid under the control of theproportional control valve 310.

The heat transfer fluid having a relatively high temperature that isdischarged from the bypass and the heat transfer fluid having arelatively low temperature that is discharged from the thermocline 100are mixed, and the mixed heat transfer fluid is heated to a properprocess temperature by the heater 210. Accordingly, the temperaturecontrol system according to the present invention has a higher heatefficiency than that of the conventional temperature control system.

In the embodiment of the present invention as described above, it isexemplified that the temperature control system according to the presentinvention is applied to one process device 510. However, the presentinvention is not limited thereto. The temperature control systemaccording to the present invention may be applied to several processdevices 510 as illustrated in FIG, 3 illustrating the construction of atemperature control system for semiconductor manufacturing equipmentaccording to a second embodiment of the present invention.

As illustrated in FIG. 3, according to the temperature control systemaccording to the second embodiment of the present invention, onethermocline 100 is connected to respective process devices 510 and 520,and supplies the heat transfer fluid to the respective process devices510 and 520. That is, the respective process devices 510 and 520 areconnected to the thermocline 100, and receive the supply of the heattransfer fluid from the thermocline 100. Here, since the respectiveprocess devices 510 and 520 connected to the thermocline 100 have thesame structure, and the heat transfer fluid circulating structure on thelines connected to the respective process devices 510 and 520 is thesame as that described with reference to FIG. 2, repeated descriptionthereof will be omitted.

In FIGS. 2 and 3, it is exemplified that the heat exchanger 10 thatexchanges heat with the thermocline 100 is composed of the evaporatorhaving a cooling cycle. However, the present invention is not limitedthereto. As illustrated in FIGS. 4 and 5, the heat exchanger of thetemperature control system according to the present invention may beconstructed to receive the supply of cooling water separately and toexchange heat with the thermocline.

Here, methods of cooling the heat exchanger 10 using a cooling cycle orcooling water may be properly selected according to the processtemperature of the heat transfer fluid. For example, in the case oflowering the temperature of the heat transfer fluid from 30° C. to 20°C., it is preferable to cool the heat exchanger 10 using the coolingcycle rather than using the cooling water. In the case of lowering thetemperature of the heat transfer fluid below zero degree, it ispreferable to cool the heat exchanger using the cooling cycle. Bycontrast, in the case of lowering the temperature of the heat transferfluid from 100° C. to 40° C., it is enough to cool the heat exchanger 10using the cooling water.

In FIGS. 4 and 5 illustrating the temperature control systems accordingto the third and fourth embodiments of the present invention, theremaining parts except for the structure of the heat exchanger 10 aexchanging heat with the thermocline 100 and the structure of thecooling device connected to the heat exchanger 10 a are the same asthose as described with reference to FIGS. 2 and 3, and thus repeateddescription thereof will be omitted.

INDUSTRIAL APPLICABILITY

As can be seen from the foregoing, the chiller system for semiconductormanufacturing equipment according to the present invention has thefollowing effects.

Since a small amount of heat transfer fluid flowing through the supplyline is heated to a desired process temperature by the heater and theheat of the heat transfer fluid being recovered to the thermoclinethrough the process device is used to control the temperature of theheat transfer fluid being supplied to the process device, thetemperature control system for semiconductor manufacturing equipmentaccording to the present invention has a higher heat efficiency thanthat of the general temperature control system.

The temperature control system according to the present inventioncontrols the temperature of only a small amount of heat transfer fluid,and thus can promptly cope with a required load.

According to the temperature control system according to the presentinvention, since several process devices can be connected to onethermocline, the temperatures of the several process devices can becontrolled using the heat transfer fluid stored in the thermocline, andthus the installation cost and scale can be reduced.

While this invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is to be understood that the invention is not limited to thedisclosed embodiment and the drawings. On the contrary, it is intendedto cover various modifications and variations within the spirit andscope of the appended claims.

1. A temperature control system for semiconductor manufacturingequipment, comprising: a thermocline for cooling heat transfer fluidaccommodated therein through a heat exchange with a heat exchanger andstoring heat energy; a supply line for controlling the temperature ofthe heat transfer fluid in the thermocline through a heater andsupplying the heat transfer fluid with a proper temperature to a processdevice; a recovery line for forwarding the heat transfer fluid havingpassed through the process device to the thermocline; and a bypass forforwarding a part of the heat transfer fluid passing through therecovery line to the supply line through the heater.
 2. A temperaturecontrol system for semiconductor manufacturing equipment, comprising: acirculation line for supplying heat transfer fluid to a process deviceand then recovering the supplied heat transfer fluid; a thermocline forcooling the heat transfer fluid accommodated therein through a heatexchange with a heat exchanger, storing heat energy, receiving a part ofthe heat transfer fluid circulating through the circulation line, andthen supplying the part of the heat transfer fluid accommodated thereinto the circulation line; and a heater for controlling a temperature ofthe heat transfer fluid being supplied to the process device through thecirculation line at a proper temperature level.
 3. The temperaturecontrol system of claim 1, further comprising a proportional controlvalve for controlling a flow of the heat transfer fluid so that a flowrate of the heat transfer fluid flowing into the thermocline through theprocess device and a flow rate of the heat transfer fluid beingdischarged to be supplied from the thermocline to the process devicesubstantially coincide with each other.
 4. The temperature controlsystem of claim 1, wherein the thermocline comprises a phase changematerial (PCM) pipe for storing thermal energy using a PCM.
 5. Thetemperature control system of claim 1, further comprising a plurality ofprocess devices connected to the thermocline so that the thermoclinesupplies the heat transfer fluid to the respective process devices. 6.The temperature control system of claim 1, further comprising anauxiliary bypass for supplying to the heater the part of the heattransfer fluid being supplied to the process device through the heater.7. The temperature control system of claim 2, further comprising aproportional control valve for controlling a flow of the heat transferfluid so that a flow rate of the heat transfer fluid flowing into thethermocline through the process device and a flow rate of the heattransfer fluid being discharged to be supplied from the thermocline tothe process device substantially coincide with each other.
 8. Thetemperature control system of claim 2, wherein the thermocline comprisesa phase change material (PCM) pipe for storing thermal energy using aPCM.
 9. The temperature control system of claim 2, further comprising aplurality of process devices connected to the thermocline so that thethermocline supplies the heat transfer fluid to the respective processdevices.
 10. The temperature control system of claim 2, furthercomprising an auxiliary bypass for supplying to the heater the part ofthe heat transfer fluid being supplied to the process device through theheater.